“These starfish feast on the coral and leave it bleached white and vulnerable to destruction in heavy storms,” says report author Professor Bernard Degnan. “But now we’ve found the genes they use to communicate, we can begin fabricating environmentally safe baits that trick them into gathering in one place.”

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Researchers from Australia and Japan worked together to become the first to decode the starfish’s pheromones. They say their solution is cheaper and more effective than current methods, which usually rely on divers picking off the starfish by hand.

According to the report, published in the journal Nature, crown-of-thorns outbreaks have a higher impact on reef health than coral bleaching and disease combined.

“No one has done anything like this,” said Degnan, from the University of Queensland. “We created an aggregation event in an aquarium, then we sequenced the proteins in the plume that it produced.”

He said it would be three to five years before the baits could be implemented in the field. “The report was phase one. Phase two is fabricating the baits, and once we have them, we’ll test them on a small scale in an aquarium.

“Up until now, many millions of dollars have been spent on trying to control crown-of-thorns on a local level. We want these baits to be deployed all around the reef. Instead of a local solution, we’re talking a regional-scale solution.”

The report’s authors sequenced the genome of crown-of-thorns specimens collected from the Great Barrier Reef and Okinawa, then conducted experiments by releasing the pheromone in an aquarium environment.

“We had a starfish at the base of a giant Y-shaped tank, and if you let plain seawater run in, it basically just sits there,” said Degnan.

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“However, if you have one arm with natural seawater and another that had travelled across aggregating starfish in a different tank, it would immediately sense that chemical and move towards the arm from where the signal came. We did this repeatedly and the data is significant statistically.”

The researchers are hopeful that a similar approach could be applied to other marine pests such as sea snails.

Associate Professor Sandie Degnan, also from the University of Queensland, said the frequency of major crown-of-thorns outbreaks had increased recently.

“There’s probably some natural cycles and quite possibly some human-induced trends as well,” she said. “When that happens the sheer number of starfish really decimates the reef.”